Trifluoroacetic acid → N-(2,3-dihydro-1H-inden-2-yl)-2,2,2-trifluoroacetamide

Reaction equation

[F:1][C:2]([F:7])([F:6])[C:3](O)=[O:4].[CH2:8]1[C:16]2[C:11](=[CH:12][CH:13]=[CH:14][CH:15]=2)[CH2:10][CH:9]1[NH2:17].CCN(CC)CC>C1COCC1>[F:1][C:2]([F:7])([F:6])[C:3]([NH:17][CH:9]1[CH2:10][C:11]2[C:16](=[CH:15][CH:14]=[CH:13][CH:12]=2)[CH2:8]1)=[O:4]

Participants

Procedure

Under N2 at −75° C., trifluoroacetic acid was added to a stirring solution of 2,3-dihydro-1H-inden-2-amine (HCl salt, 8.0 g, 47.2 mmol), Et3N (14.9 ml, 106.7 mmol) and THF (160 ml). After the solution was allowed to warm up to rt, it was partitioned between H2O and DCM. The organic layer was dried over MgSO4 and evaporated in vacuo. The residue was triturated with hexanes: Et2O (1:1) to obtain the product as a white solid (8.9 g, 82% yield). 1H-NMR (400 MHz, CDCl3) δ 7.28-7.20 (m, 4H), 6.50 (s, 1H), 4.81-4.74 (m, 1H), 3.38 (dd, J=16.4, 7.1 Hz, 2H), 2.89 (dd, J=16.3, 4.2 Hz, 2H).